184 



lowing table, compiled from numerous measurements taken during a 

 period of > ears shows the maximum, minimum and average length of 

 fibre for some of the more important varieties, and also the average 

 diameter of the same : — 



Length and diameter of the principal cotton fibres. 





Length of Staple. 



Average 



Variety. 









diameter ol 





Maximum 



Minimum. 



Average. 













Staple. 





Inches 



Inches. 



Inches. 



Inches. 



Sea Island 



1.80 



1.41 



1 61 



.000640 



New Orhans 



1.16 



.8s 



1 .02 





Texas 



1 12 



.87 



1.(0 



.000763 



Upland 



1 0<i 



.81 



.'J3 



.000763 



Egyptian 



1 .52 



1.30 



1.41 



.000655 



Brazilian 



1.31 



1.03 



1.17 



.000790 



Indian varieties : 











Native 



1.02 



.97 



.89 



.000844 



American seed 



1.21 



.95 



1 08 



.000825 



Sea Ishmd seed ... 



1.65 



1.36 



1.50 



.000730 



From the above table it will be seen that, as a rule, the longer the 

 fibre the less its diameter. The extreme variation jin length of the 

 above fibres, from the figures as shown in the table, is from 0.25 to 

 . 30 inch. In proportion to their size the variation in diameter is much 

 greater than that shown for the length. 



If a very imma ure boll be cut transversely the cut section w T ill 

 show that it is divided by longitudinal walls into three or more divi- 

 sions, and the seed will be shown attached to the inner angle of each 

 division. The seeds retain this attachment until they have nearly 

 reached their mature size, and the growth of lint has begun on them, 

 when their attachments begin to be absorbed and by the increased 

 growth of the lint the seed are forced to the centre of the cavity. 

 The development of the fibre commences at the end of the seed far- 

 thest from its attachment, and gradually spreads over the seed as the 

 process of growth continues. The first appearance of the cotton fibre 

 occurs a considerable time before the seed has attained its full growth, 

 and commences by the development of cells from the surface of the 

 seed. These cells seem to have their origin in the second layer of cel- 

 lular tissue, and force themselves through the epidermal layer, which 

 seems to be gradually absorbed. The cells which originate the fibre 

 are characterized by the thickness of their cell walls when compared 



